Encapsulation of lactic acid bacteria and Bifidobacteria using starch-sodium alginate nanofibers to enhance viability in food model

The aim of this study was to nanoencapsulate some probiotic strains of lactic acid bacteria and Bifidobacteria within corn starch (CS) and sodium alginate (SA) nanofiber mats using the electrospinning method to enhance survival and viability in yogurt as a food model. The control and probiotic-containing nanofiber mats had negative zeta potential of -10.83 and -12.57 mV. The SA/CS nanofibers had a greater protective effect on LAB compared to Bifidobacteria in an acidic environment. LAB count within nanofiber mats was reduced by 0.19, 0.85, and 1.05 logCFU, and of Bifidobacteria by 0.27, 0.46, and 1.24 logCFU, at 55, 60, and 65 degrees C, respectively, which was lower than cell loss of free cells. After 20-day storage of yogurt, the count of nanoencapsulated LAB and Bifidobacteria declined 0.19 (97.9% survival) and 0.28 (96.9% survival) logCFU, respectively, while 1.12 (87.7% survival) and 1.25 (86.3% survival) logCFU of cell loss was found for free cells. Practical applications Although probiotic bacteria have a great potential in producing functional metabolites and components with antimicrobial, antioxidant, and health-promoting properties, their survival, and viability during food processing are affected by factors like heat, pH and acidity, food molecular structure, and chemical compounds of the food matrix. To protect probiotics against processing conditions in food preparation, increase their survival and stability in the food matrix, nanoencapsulation techniques are used. The preferred nanoencapsulation methods are those with the least damage to the probiotic cells. So, the results of this study will be useful to design the proper formulations of coatings for probiotics used in food products.